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61  Using Arduino / Programming Questions / Re: Help with a pulse detection func on: January 12, 2013, 07:22:18 pm
use them:

analogread
map
digitalwrite
62  Using Arduino / Interfacing w/ Software on the Computer / Re: fast transmission of much data on: January 12, 2013, 06:50:24 pm
Data is collected from radio rx and sent after sync code, I always send the next arriving 250 slopes (ASK) then to be evaluated.
I now use 115200 baud rate and not use serial monitor anyway.
And I forget too mention : Now I am convertin g to string with println(strval) and yes,this is good and easy to parse.
it was exactly what I thought, too: needs more memory / is easy to parse (for example 9999 as string is each a byte because you use only the range 0..9) Thats why an idea would be to send integers up to 65536 in two bytes. (the data is always <25000). That should only need 2 bytes / transmission , insteas of e.g. 5bytes for "25000" as string.



63  Using Arduino / Interfacing w/ Software on the Computer / fast transmission of much data on: January 12, 2013, 05:44:23 pm
Hello,

Arduino is supposed to transmit array of integer to a windows software I am going to write
array length = 250, array elements = integer
How can this be transmitted -serial- fast ?
Any trick?, for example transferring some bits can be transferred by one byte with bitshift operations.

Thank you
64  Using Arduino / Project Guidance / Re: PT2260 / SC2260 key fob, get signal - AGC ? on: January 11, 2013, 09:30:43 am
To keep you informed:

First, I really wondered why there is no repeating change of 1 and 0 (on / off - with Duty cycle = 50% maybe ~ 30 times) .
Now, I wrote that simple sketch because I read (mikroElektronika -  How can read PT2260's datas with PIC):
Quote
by dhouston
The simplest method is to wait for the long space at the end of the first transmitted copy and then use the CCP hardware to capture the pulses and spaces of the second transmitted copy.

readin.ino
Quote
// 11.JAN.2013

int pin = 11;
boolean w = LOW;
unsigned long md = 500;

void setup()
{
  pinMode(pin, INPUT);
  Serial.begin(9600); 
  Serial.println("read_in\n");
}

void loop()
{
  if (Serial.peek() == 'c') {
    w = !w;
    Serial.print("W changed to: ");
    Serial.println(w ? "HIGH" : "LOW");
    Serial.flush();
  }
  if (Serial.available()){
    int k = Serial.parseInt();
    if (k>0){
      md=k; 
      Serial.print("min duration changed to: ");
      Serial.println(md);   
    }
  }
  unsigned long duration = pulseIn(pin, w);
  if (duration>md) {
    Serial.print(w ? "HIGH" : "LOW");
    Serial.print(", length = ");
    Serial.println(duration);
  }
}

Honestly, it would not be necessary to make this code so long but it was important for me to change the variables (w: waiting for low/high; md:minimal duration) on the fly.

Very happy now because the button press is recognized, now I will extract the code that follows and will evaluate it...
65  Using Arduino / Project Guidance / Re: PT2260 / SC2260 key fob, get signal - AGC ? on: January 10, 2013, 12:44:23 pm
AFAIK, the receiver's AGC can be made "ready" by turning the carrier frequency on and of many times (tx sends: 01010101...) so that the receiver is ready to get the following data.

Maybe I just misused the word AGC - however I mean what I described above to make a kind of match between receiver /transmitter.

For example, I received a raw VirtualWire encoded signal and noticed that it also sends ~ 30times on-off with same duration (like a Manchester coded "1"  = "01" or "10" )
66  Using Arduino / Installation & Troubleshooting / Re: Windows 7 and driver signing on: January 10, 2013, 12:35:49 pm
Try this
http://www.techspot.com/community/topics/how-to-install-use-unsigned-drivers-in-windows-vista-7-x64.127187/
solution #2
if this doesn't work, I think I cannot help you, sorry.
67  Using Arduino / Project Guidance / PT2260 / SC2260 key fob, get signal - AGC ? on: January 10, 2013, 10:27:49 am
Hello,

do you know if I can get signals with a simple ASK receiver (those tiny chinese ones for 1-2$, example) sent by an ASK transmitter (of course same frequency, this one) ?

It is PT2260 coded, I opened it, there was written SC2260 (they're technically the same).

I already read the data sheet but only found something to the coding itself.
And I was not able to find out whether there is some kind of AGC used, I think it has to otherwise a matched receiver wouldn't be able to get the signal, I wrote an interrupt based Arduino sketch looking for AGC bits (0,1,0,1,... alternating, each the same duration) and I proved that it works with an easy transmitter I found at home. But why does this transmitter not send any AGC or does it?

Thank you
Regards

68  Using Arduino / Installation & Troubleshooting / Re: Windows 7 and driver signing on: January 10, 2013, 10:16:10 am
look in device manager and search for the Arduino, this should be a question mark - unknown device
right click -> install driver manually.

worked for me on windows 8, 64bit
69  Using Arduino / Project Guidance / Re: Alarm system and radio transmission on: January 08, 2013, 02:35:34 pm
What do you think about the idea (http://arduino.cc/forum/index.php/topic,140776.msg1058205.html#msg1058205) to control whether the cable to the siren was cut? Can this method work - the idea is that there is a short circuit from Arduino GND to a pullupped Arduino Digital In, if the cable is cut anywhere - this is like a switch - it will be recognized. How to make the alarm then?
70  Using Arduino / Programming Questions / Re: serial.avaiable in loop on: January 06, 2013, 02:20:43 pm
Ah ok. Thank you - That is very useful for me then smiley
71  Using Arduino / Programming Questions / serial.avaiable in loop on: January 06, 2013, 02:04:13 pm
Hello,

does Arduino need some time to check
Code:
if (Serial.available()>0)
in  the "loop" ?

How much is this approximately?

Thank you
72  Using Arduino / Project Guidance / Re: Alarm system and radio transmission on: January 05, 2013, 05:44:02 pm
@karlok - a rolling code can be defeated fairly easily once you recognize that it is being used.  A replay attack just replays the last message and would of course fail.  Actually determining the rolling key algorithm will allow you to modify the next message and "play" it with the right key.
Hello, I still am not able to beleive that. How would you do so. For me a rolling code is an always changing code that is created by using a secret key and a message(message = counter in this case).

And I am also interested in the outdoor cable idea where I drew the picture.
73  Development / Other Software Development / Re: [MOD] Arduino Enhanced Release 1.0.3 for Windows (installer, drivers, etc) +SRC on: January 05, 2013, 08:28:22 am
Ok, works now. I backuped your modified dll however smiley-wink Thanks
74  Using Arduino / Project Guidance / Re: Alarm system and radio transmission on: January 05, 2013, 07:49:09 am
Hello,

thank you very much for your answers!
@jroorda: This is an important question to ask. I think other factors should be regarded more than the encrypted wireless transmission that might be an overkill, as I understood the answers like. It has to be reliable always.
Maybe the thief is able to jam the transmission frequency, because he thinks that will avoid the base station getting  the "alarm"-signal, but in fact he just prevents my "OK"-signal to reach the base station and that will result Alarm before even getting in. This is also a problem because this is a false-positive, the alarm can be triggered without making physical damage. Do you think this is a problem for the system?
@djjoshuad:  I read your long answer with interest and I think I will concentrate of those 99% of burglars that are not electronically skilled. However, I think it is not able to get the key behind the rolling technique, Rolling code - Wikipedia, the free encyclopedia, RKE Analysis, a replay attack will fail because the "OK"-signal always changes.
@wildbill,PeterH: I am still not sure whether I should add encryption to the system or not, it also makes the system more fragile because it is not simply get-ok-signal or not get it, but also checking whether the decrypted counter is in a specific allowed range.
For me the wired solution would be a sophisticated one because the alarm station and the base station are in different floors and cable laying doesnt look that nice and is difficult to hide.
I am not only interested in the factor of wireless signal but also others like the alarm device (siren, strobe,...) For that I am planning to do the following:

If the cable is cut, the lightblue cable is also cut and that is recognized by the Arduino, but how to trigger the alarm then if you know you cannot trigger it?!
75  Development / Other Software Development / Re: [MOD] Arduino Enhanced Release 1.0.3 for Windows (installer, drivers, etc) +SRC on: January 04, 2013, 06:16:56 pm
Hello,
I need it because I want to look how the program looks like resetted. For example now, I am working with an alarm system and if the sensor is triggered it will send some signals via radio transmission and if not it sends some other signals, and then I just reset Arduino and troubleshoot again why/why not something was triggered. Alternatively, I could change the code so that the alarm can be changed if the situation changed, e.g. stop blinking led when reed switch is closed again. but i like this reset-feature smiley-wink
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